1. Technical Field
The presently disclosed embodiments are directed to using a property of media for producing booklets bound to form books.
2. Brief Discussion of Related Art
A typical method of binding books includes forming a number of booklets which are then assembled together to form the final book. Each booklet is made up of a number of signature sheets folded in the middle and include printing on four sides of the folded sheet.
When forming books in this manner, the maximum booklet size must be determined. This determination is a function of the physical constraints of the machine itself and the thickness of the paper to be used in forming the booklets. A machine typically can only process a stack of sheets having a specific maximum thickness. With physical constraints of the machine being set, once the type of paper is selected, the machine operator stacks up the paper and measures its height. The maximum number of sheets of the particular paper that fit with in the capabilities of the machine determines the maximum booklet size.
One other calculation typically performed by printing machine operators is determining the amount of creep. As stacked sheets are folded, the edges of the sheets create a shingling effect with the edges of the innermost sheet extending farther than the edges of the outermost sheet. Therefore, the edges of the pages extend from the folded book more and more as they approach the center of the bound booklet. This difference between the edges of adjacent sheets is known as creep. The amount of creep depends on the thickness of the sheets and the number of sheets in the booklet.
Creep creates problems when binding books. The inside margin will be smaller for outer pages of the booklet than for the inner pages. If the margin is not adjusted the image near the crease on the outer pages may be obscured. In addition, in order to create a booklet with uniform edges, the edges are trimmed after the booklet is creased. When the edges are trimmed, the inner pages are narrower than the outer pages. If the images on the pages were set the same for each page, the image would appear to be misplaced on the pages after the trimming. For large amounts of creep, the image on some of the pages may be trimmed off. In order to correct this problem, printers adjust the image placement on the sheets.
Operators typically manually measure the total creep by using a test stack and determine the creep for each pages that the creep can be adjusted for. This is a time consuming process that must be performed for each job.